Safety device for elevators



A. HEISLER. SAFETY DEVICE FOR'ELEVATORS.

APPLICATION FILED MAR- 31,1920- Patented Nov. 16, 1920.

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UNITED STATES PATENT OFFICE.

AARON HEISLER, 01F PITTSBURGH, PENNSYLVANIA.

Specification of Letters Patent.

Patented Nov.16, ieeo.

Application filed March 31, 1920. Serial No. 370,110.

To aZZ'w 7mm it may concern Be it known that I, AARON HEISLER, a citizenof the United States, residing at Pittsburgh, in the county of Alleghenyand State of Pennsylvania, have invented certain new and usefulImprovements in Safety Devices for Elevators, of which the following isa specification. I

This invention relates to safety devices for electric elevators in whicha switch, carried by the cage and inserted in the electric circuit whichactuates the lifting 1nechanism, is controlled by means of a projectionarranged in the elevator well; and it consists in the novel constructionand com-. bin-ation of the parts hereinafter fully described andclaimed.

In the drawings, Figure 1 is a diagram of an elevator provided with asafety at tachment according to this invention. Fig. 2 is a side view ofthe safety device drawn to a larger scale and showing the casing insection. Fig. 3 is a front view of the device shown in Fig. 2.

The elevator is an electric elevator oi any approved construction havinga cage 2 which is slidable vertically in an elevator well 3, and whichis actuated by lifting mechanism of any approved kind. A casing sissecured in the elevator cage, and incloses a switch having a stationaryand insulated contact member 5. A switch lever 6 is pivoted in thecasing on a pin 7 and it carries an insulated contact member 8. Thecontact members are inserted in the electric circuit 9, and when incontact they permit the current to pass to the electric liftingmechanism. /Vhen the contact members are separated the circuit broken,and the lifting mechanism is stopped, but the circuit may be so arrangedthat the current 18 only partially cut off from the lifting mechanism sothat the latter is caused to operate slowly.

The switch operating mechanism on the cage is actuated by a stationarycam or projection 10 secured to one side of the well 3 at any suitablepoint. This camis preferably formed of a curved spring which is curvedoutwardly and secured to the well at each end. A cam or eccentric 12 ismounted on a pin 14 in the casing 4, anda ratchet toothed wheel 15 issecured to one side of this cam. The cam 12 has recesses 16 in itsperiphery, and 17 is a spring check pawl which is secured to the casing,and which engages with the said recesses. Any other approved checkmechanism may however be used in carrying out this invention provided itwill prevent the cam 12 from being improperly moved.

lever 18 is pivoted on the pin 14:, and 19 1s a pushing pawl pivoted toone end of the lever and engaging with the teeth of the wheel 15. Thecam 12 is arranged to one side of the, switch lever 6, and engages withit when partially revolved. The other end portion of the lever 18 has alongitudinal slot 20, and 21 is a slide which is arranged horizontally,and which works back and forth on a guide 22 secured to the casing. Anarm 24 projects vertically from one; end portion ofthe slide and has apin 25 at its upper part which engages with the slot 20. The other endportion of the slide 21 carries a roller 26 which is mounted on a pin27,

Two curved arms 30 are provided, and are pivoted at their opposite endsto the casing 4 or other suitable support, by pins 31. The adjacent endportion of the arms 30 have slots 32 which engage with the pin 27, andthe arms normally position and support the outer end portion of theslide which projects through an opening 33 in the side of the casing a.The roller 26 engages with the cam or projection 10, and when the slideis pushed back by the cam, the switch lever is operated and the contactmembers are separated.

Each elevator can be provided with a series of safety devices similar tothose hereinbefore described, and the cams or projec tions lOare put atsuitable points in the elevator well so as to stop the cageautomatically at any desiredlevels, and to make it move slowly atpredetermined points, such as when the cage approaches a landing place.-The switch mechanisms are preferably arranged side by side in the cagewhen a plurality of them is. provided, but each mechanism is arrangedtowork independently of the others. The ratchet toothed wheel '15 neednot have teeth all around its periphery, and a single tooth engaged bythe pawl 19 would be effective to open the switch. The provision of aseries of teeth however enables the device to be set and adjusted tosuit the requirements of different elevators, or diiferently locatedprojections 10' in the same elevator shaft or well. When the elevatorcage has been stopped automatically by the safety device, the elevatorman in the cage re-sets the ratchet toothed wheel and pawl by hand totheir original positions stops, which will occur on in order that thecage may again beoperated. The check pawl 17 prevents the switch fromclosing when the roller '26 is moved past the projection lO before thecage high speed elevators such as are now used in high buildings. 7

What I claim is:

-1. Ina safety'device, an electric switch adapted to be secured in anelevator cage and provided with a :pivoted switch lever, av stationaryprojection adapted to be secured in the elevator/we'll, a cam for movingthe said lever to open the switch, a cam operating lever pivotedconcentric with the earn, a :pawland iratchet'mechan sm operatlvelyconnecting the said cam operating lever with the cam, vided witha rolleratone end tor engaging withithe:saidzproj ection and having its-otherend operative'lyiconnected with "the cam op erating lever, and a springwhich normally projects the slide so that its roller will engagte withthe said projection.

a safety device, an electric switch 7 provided with a pivoted operating"lever and adaptedto be carried by an electric a horizontal slide ;pro--V the outer end portion of the said normally holding," tin position tobe en- Y gaged by the said-projection cage, astationary projectionadapted to be secured in the elevator well, a vrevolulole cam foroperating the switch lever, a toothed wheel secured to'the. said cam, alever pivoted concentric with the toothed, wheel and provided'with apawl for engaging with its teeth, and a horizontal slide which is pushedback by the said projection and ates the last said leven 3. In a safetydevice, an electric switch provided with a pivoted operating'lever andadapted which opera stationary pro ection adapted to be se pivoted armshaving their adj acent send portions pivotal-1y and "slidably connectedwith In testimony whereof I haven fixed :rny

signature. V

AARON HEISLER.

to bejcarried byan elevator cage;

is 1 operatively connected I slide and

